How do you time a TD ninety fitted with a 200TDI

OK I have spent hours searching the forums and now I give in.
Can anyone give me a step by step guide on how to change a timing belt on a TD ninety fitted with a 200TDI engine.
After reading everything I can find it seems simple to fit a 9.5 mm drill bit or the correct timing pin tool into the bottom of the bell housing into a groove on the flywheel which if the woodruff pin on the front of the crank is at 12 o,clock then this is top dead centre?.. Simple

I think not the bell housing does not have a threaded hole in the bottom it has one at the top.
It also has two grooves in the flywheel of which neither line up with the hole on the bell housing when the woodruff key is at 12 o,clock why are there two grooves?

I believe that when a conversion is carried out then the TD bell housing plate is swapped onto the rear of the TDI engine but surely this prevents the crank from being locked into the correct position when timing the engine.

Help!!!!!!!

Timing using the pins and drill bit's is as per manuals . Use tipex on the pulleys and on the timing cover , as long as they line up when new belt is fitted after turning engine over twice by hand , youre good to go . Did'nt know about pin hole in bell housing , but you can still pin pump and then tipex the pulleys etc , pump is the hardest to get belt on as the little bugger keeps trying to rotate . !!! enjoy